Present day semiconductors utilize decoupling capacitors built using transistor gates. Decoupling capacitors are needed to prevent voltage drops in the internal supplies of an integrated circuit when large amounts of switching activity occur. However, the advances in technologies are requiring the use of thin gate oxides that result in a non-ideal gate capacitor current leakage. In addition, these capacitors consume valuable circuit layout area and thus the utilization of such capacitors is limited. Gate capacitor current leakage also results in wasted power consumption that is critical in low-power applications. The leakage may be mitigated, but at the expense of total decoupling capacitance and process complexity. Because of a large distance between the decoupling capacitor and active circuitry, the high frequency response of the decoupling capacitor is limited. The distance must be large because placement of the decoupling capacitor is limited and typical placement of the decoupling capacitor is further removed from active circuitry than desired. Existing decoupling capacitor structures therefore either suffer from power consumption issues, size issues and/or electrical efficiency.
Skilled artisans appreciate that elements in the figures are illustrated for simplicity and clarity and have not necessarily been drawn to scale. For example, the dimensions of some of the elements in the figures may be exaggerated relative to other elements to help improve the understanding of the embodiments of the present invention.